What gauge wire should I run to the rear for a reciever mounted winch. Warn 8000.

 

A simple search of Warn's website provided this:

M8000 SPECS/PART NUMBERS
Part number: 26502 (12V)
Rated line pull: 8,000 lbs., (3630 kgs.) single-line
Motor: Series Wound, 12V 4.8 hp
Electrical controls: Contactor
Remote Control: Remote switch, 12 ft (3.7m) lead
Geartrain: 3-Stage Planetary
Gear ratio: 216:1
Clutch (freespooling): Sliding Ring Gear
Brake: Automatic Direct Drive Cone
Drum diameter/Length: 2.5 in/9.0 in (6.4cm/23cm)
Weight: 74 lbs. (34kgs.)
Wire rope: 100 ft, 5/16 ft (30m, 8mm)
Fairlead: Roller
Recommended Battery: 650 CCA minimum for winching
Battery leads: 2 gauge, 72 in (1.83m)
Finish: Argent Gray Powder Coat

12V DC PERFORMANCE SPECS

Line Pull Lbs / Motor Current

0 /80 amps
2000 /200 amps
4000 /285 amps
6000 /350 amps
8000 /435 amps

SO, if the leads are 2 gauge, probably a good idea to run that from the battery. I'd also install an appropriate circuit breaker or fuse inline not too far from the battery.

 

If its a receiver mount winch in the back of the truck and the battery is under the hood, there is a fair amount of distance that needs to be considered ~ 15ft. There is a going to be a significant voltage drop over that distance, especially at the peak draw of 8000lbs. / 435 amps.

Check here to determine the correct wire you want to install given your own personal safety factor, budget, etc. If you want 12V at 15ft. and still want 435 amp capacity, the calculator says that even using 4/0 AWG only gets you 11.2 volts at the end. Of course that's at max pull rating.

You will have to decide...

http://www.gadgetjq.com/wiring_size_guide.htm

 

I have a 2/0 wire I made going from my front battery to a rear battery. Powers a 12,000lb wench with no problem. Although it helps having the second battery right there. My wire has never even gotten warm, stays cool as can be.